#include <bits/stdc++.h>
using namespace std;
#define PI 3.1415926
#define   SQUARE(x) ((x)*(x))
//double SQUARE(double x) { return x*x;}

long long f[100]={1,1,2,3};

void w1()
{
	int a,b,n, k;
	scanf("%d", &k);
	double Sn=1;
	n = 1;
	for(;;){
		if(Sn>k) break;
		n++;
		Sn += 1.0/(double)n;
	}
	printf("%d", n);
}

int main()
{
	w1();
  return 0;
}
